Explain the Sub-Culturing?

Microbiological studies require microorganisms in pure form, i.e., a single type of microorganisms should be present in a culture. Maintenance of these pure cultures in laboratory is must. Preparation and maintenance of these pure cultures can be achieved by transfer of culture from one medium to another or from their parent growth source to another. The procedure is called sub-culturing. This technique is of basic importance and should be carried out by practicing aseptic technique. The term picking off is used when transfer is made from solid to liquid media.